1. Field of the Invention
The present invention relates to a vehicle indicator lamp that has a transparent cover and more particularly to a horizontal light irradiation mechanism of a vehicle indicator lamp.
2. Prior Art
Recently, a transparent cover has been increasingly employed in vehicle indicators instead of a front lens so as to impart transparency to lamp fixtures.
Conventionally, a reflecting mechanism has been employed in a lamp fixture for diffusion-reflecting the light from a light source forward so as to obtain a desired lamp fixture light distribution performance.
However, in a vehicle indicator lamp that uses the above-described lamp fixture, the problems as described below would occur when a wide range of horizontal light irradiation is demanded.
More specifically, in the front turn signal lamp as shown in FIG. 8, in view of improving visibility of the lamp fixture by a driver of another vehicle, it is desired that light irradiation is performed in a light distribution pattern that horizontally diffuses light to the inside with respect to the width of the vehicle at around 45xc2x0 and also to the outside with respect to the width of the vehicle at around 80xc2x0 relative to the optical axis Ax of the lamp that extends in the longitudinal direction of the lamp. However, the lamp fixture in which the light from light source 4 is diffusion-reflected forward by a reflector 2 as shown in FIG. 8 does not make the light irradiation at a wide horizontal diffusion angle due to its structure. Direct light from the light source 4 is merely directly diffusion-irradiated through the transparent cover 6. Therefore, it is not possible to perform light irradiation at an angle that exceeds the angle xcex8 defined by the positional relationship between the light source 4 and the side edge of the transparent cover 6.
In view of the above disadvantage with the prior art, the object of the invention is to provide a vehicle indicator lamp that has a transparent cover and is capable of performing horizontal light irradiation at a wide angle.
In the present invention, the above object is accomplished by a unique structure for a transparent cover structure.
More specifically, the present invention is for a vehicle indicator lamp that has a light source disposed on its optical axis, a reflector having a reflecting surface that diffusion-reflects the light from the light source forward, and a transparent plain cover provided in front of the reflector; and in the present invention, a horizontal deflection lens portion is formed in the center area of the transparent cover and near the lamp""s optical axis so that the horizontal deflection lens horizontally deflection-permeates the direct light from the light source in a direction away from the lamp""s optical axis.
The xe2x80x9ctransparent coverxe2x80x9d is not limited to a particular structure so long as it is transparent and plain. It may be disposed in the position of an outer lens (normally employed as a front lens) or disposed in the position of an inner lens within the lamp fixture.
The xe2x80x9chorizontal deflection lens portionxe2x80x9d is not limited to a particular structure so long as it can horizontally deflection-permeate the direct light from the light source in a direction away from the lamp""s optical axis. For example, the xe2x80x9chorizontal deflection lens portionxe2x80x9d can be formed of a single lens element or a plurality of lens elements. It can be formed on the front surface or on the rear surface, or it can be formed on both front and rear surfaces of the transparent cover. Furthermore, the xe2x80x9chorizontal deflection lens portionxe2x80x9d can be formed over the center area entirely, or such a portion can be formed on just a part thereof.
As seen from the above, in the vehicle indicator lamp according to the present invention, the reflecting surface of the reflector diffusion-reflects the light from the light source forward, and the transparent plain cover is disposed in front of the reflector. Accordingly, a predetermined light distribution can be obtained while imparting transparency to the lamp fixture. Furthermore, the horizontal deflection lens portion that horizontal deflection-permeates the direct light from the light source in a direction away from the optical axis is provided, and such a lens portion is formed on the center area of the transparent cover and near the lamp""s optical axis. Accordingly, it is possible to perform light irradiation at a wide horizontal diffusion angle that has never been achieved by conventional art, since the light irradiation of conventional art is performed only with the diffusion reflecting light from the reflector and with the direct light that is from the light source and merely passes through the transparent cover.
In view of the above, the present invention provides a vehicle indicator lamp having a transparent cover that performs a horizontal light irradiation at a wider angle.
With the horizontal deflection lens portion formed on the center area of the transparent cover as described above, this area is no longer plain. However, the light source bulb is positioned in the back of such a center area. Accordingly, the area of the reflecting surface of the reflector, which is shielded by the horizontal deflection lens portion and is not visible when the lamp fixture is viewed from the front, is quite small. The horizontal deflection lens portion, on the other hand, prevents the light source bulb, the portion where the light source bulb is attached to the reflector, etc., from being viewed from the front. Moreover, the horizontal deflection lens portion can appear to be floating in the center area of the transparent cover, while the reflecting surface of the reflector can appear to be far in the back through the plain peripheral portion. Accordingly, the lamp fixture of the present invention provides a good three-dimensionality and depth. Therefore, the present invention improves the appearance of a lamp fixture compared to that of a lamp fixture in which the whole area of the transparent cover is formed plain.
The structure of the xe2x80x9creflecting surfacexe2x80x9d is not limited to particular one so long as it diffusion-reflects the light from the light source forward. However, it can be designed so that substantially the entire amount of reflecting light from the reflecting surface is irradiated to the peripheral area at the outer periphery of the center area of the transparent cover. With this structure, diffusion-reflecting control by the reflecting surface and deflection permeation control by the horizontal deflection lens portion can be separately performed almost completely. Thus, the lamp fixture performs light diffusion control with high accuracy.
The degree of horizontal deflection angle of the direct light from the light source by the xe2x80x9chorizontal deflection lens portionxe2x80x9d is not limited to a particular angle. It is preferable that at least a portion of the horizontal deflection lens portion is formed so as to horizontally emit the direct light from the light source to the lamp""s optical axis at an opening angle of 60xc2x0 or greater. With this structure, the visibility of the lamp fixture by a driver of another vehicle can be sufficiently improved.
In the above structure, the horizontal deflection lens portion can be formed of a plurality of lens elements divided into vertical stripes. With this structure, the deflection permeation light can be obtained in the form of a collection of the deflection permeation light from the respective lens elements. As a result, an even more accurate deflection permeation control can be performed.
In the above case, each of the lens elements can be formed so as to enable the direct light from the light source to deflection-permeate only by the refractive action. If the direct light from the light source is deflection-permeated using not only the refractive action but also the internal reflecting action, the light irradiation can be performed at a further wider angle.